Evaluating the techniques for a tiered testing approach to dredged sediment assessment-a study over a metal concentration gradient

• Published in: Environmental toxicology and chemistry Vol. 18; no. 11; pp. 2600 - 2610
• Main Authors: Porebski, Linda M., Doe, Kenneth G., Zajdlik, Barry A., Lee, Deanna, Pocklington, Patricia, Osborne, James M.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Periodicals, Inc 01-11-1999; SETAC
• Subjects: Amphipoda; Animal, plant and microbial ecology; Bacteria; Bioassays; Biological and medical sciences; Canada, New Brunswick, Belledune Harbour; Echinoidea; Fundamental and applied biological sciences. Psychology; General aspects. Techniques; Interpretation criteria; Macoma balthica; Metals; Methods and techniques (sampling, tagging, trapping, modelling...); Sediment; Tiered testing; Canada; North Atlantic; North America; Atlantic Ocean; America; ANW, Canada, New Brunswick, Belledune Harbour; Benthic organism; Bioassay; Sediments; Heavy metal; Marine environment; Pollutant; Bivalvia; Macoma balthica; Water pollution; Measurement method; Invertebrata; Mollusca; Biological accumulation; Concentration gradient
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620181130

A sediment quality triad approach was used to evaluate Environment Canada's battery of marine bioassays and the proposed pass/fail criteria along a metals gradient in Belledune Harbour, New Brunswick, Canada. Most assays performed consistently, but certain tests provided less response than expected at the more contaminated stations (amphipod survival and light reduction in photoluminescent bacteria tests passed according to proposed pass/fail criteria). Echinoid fertilization tests were quite sensitive. Bioaccumulation of lead and benthic community structure were related to bulk sediment values (at α = 0.1). Test interpretation criteria appear reasonable, but as the response rate was low in certain tests, further assessment is recommended. With respect to species suitability, only the clam Macoma balthica used in the bioaccumulation test was thought to be less than optimal for routine use on a large scale because of practical handling and cost considerations. Canadian draft Interim Sediment Quality Guidelines, which the Disposal at Sea Program may use for screening purposes in a tiered testing approach, were used in this study as the chemical benchmarks to select test stations on the basis of the relative probability of effects. Guidelines at the threshold effects level (TEL) performed well in the study as levels below which unacceptable biological effects were unlikely to occur. The ratio of simultaneously extractable metals to acid volatile sulfides was also used in addition to the guideline levels to help explain responses (or lack thereof) along the gradient. Each of the chemical approaches was useful in the prediction/explanation of some but not all of the responses seen in the toxicity and/or benthic community results.